High-gain Signal Processing Method

With the rapid development of stealth technology and LPI radar, the SNR of the target detection is usually low, so the high-gain signal processing under the low SNR are the research hotspot for the radar's target detection. In this dissertation, the Keystone transform based on coherent integration and the Hough transform based on non-coherent integration are researched to detect the dim target.Without knowing the speed of target, the range migration due to the target travel in the Coherent Processing Interval (CPI) can be corrected by the Keystone transform. So the performance of coherent integration can be guaranteed. Firstly, the principle of the Keystone transform is illustrated. Secondly, LFM-CW radar echo-model's discussion show on the range migration, and range migration's correction method and steps by the Keystone transform are described. Finally, the target detection's performance improvement using the Keystone transform under low SNR is proved by the data simulation.Use the idea of TBD, dim target's track is reached through a joint multi-frame data processing is reached by the Hough transform. Firstly, the principle and detection performance of the Hough transform are illustrated. Secondly, some key steps of the Hough transform are researched: quantization interval of the parameter space, weighted accumulation mode based on voting confidence coefficient, peak extraction based on gravity theory to determine the target's track. Finally, effectiveness of dim target's track using the Hough transform is demonstrated by the data simulation.